Temperature sensors are used in many areas of process automation engineering in order to measure temperatures of media, preferably in containers or pipelines. In certain industrial areas, for example in the foodstuffs industry or in the pharmaceutical industry, particularly special requirements are in place with respect to hygiene. Therefore, all parts in contact with the medium must be properly cleaned. For example, the standardized cleaning method, CIP, in which all surfaces in contact with the media are cleaned according to standardized methods without disassembly of a process system In particular the connecting parts of process connector—container tubes are very critical with respect to the cleaning requirements.
Temperature sensors for hygienic applications feature different process connectors. Known process connectors are the milk tube screw connection per DIN 11851 or a clamp connection per ISO 2852 or DIN 32676. Conventional temperature sensors with a clampable process connector, such as the TM4901 which is produced and sold by the firm of ifm electronic gmbh, as a rule feature a conical flange which is clamped to a corresponding opposing connector. A clamp surface at the upper side of the conical flange is required for the clamp connection and the bracket which is produced with the clamp connection engages thereon. The opposing connection is normally welded in the container wall or tube wall as a short pipe. The tube-shaped temperature probe extends through this short pipe into the corresponding medium.
In addition to the temperature tube probe and the conical flange, a typical temperature sensor also features a housing with evaluation electronics and plug connector or cable lead. The conical flange and the actual sensor housing are generally welded to each other.
Since the conical flange in such temperature sensors for hygienic applications is manufactured from solid material, temperature sensors are accordingly expensive, complicated to manufacture and also heavy. As a rule the conical flange must be produced by external companies which requires expensive logistics for sensor manufacture.